An Australian company is introducing its own version of bitcoin that will let homeowners and businesses sell excess energy generated from their rooftop solar panels to neighbors, without a middleman taking a cut.

As of Monday, Perth-based Power Ledger had sold about 57 percent of the 100 million so-called “power tokens” offered at 8.8 U.S. cents a piece since Sunday. A $25,000 cap has been installed to discourage large entities from controlling the market.

“This will make solar panels more viable financially and improve efficiency in the energy market,” Jemma Green, the company’s co-founder and chair, said in an interview. “It will also allow mum-and-dad investors who want to support renewable energy to buy small stakes in large-scale, community-owned solar projects.”

According to a RenewEconomy report in April, Australia’s solar power capacity “is expected to double over the next few years as households continue to invest in rooftop panels to reduce electricity bills and the large-scale solar sector takes off after years of promise.”

About 5.6 gigawatts of the nation’s total solar capacity of 6 gigawatts comes from rooftop panels, with the balance derived from large-scale projects, according to RenewEconomy. While at this stage they only meet about 3.3 percent of the nation’s total energy demand, the panels are on 21 percent of suitable Australian rooftops, the highest penetration of rooftop solar in the world, it said.

The tokens being issued by Power Ledger, started in May 2016, will also let solar farms sell electricity to individual customers, and apartment buildings and offices trade energy from their rooftop solar panels, Green said.